JP4318081B2 - Control device for automatic transmission - Google Patents

Abstract

In executing an ETC cooperative downshift operation based on a driver's intent to decelerate, this system executes an engine output increasing control (e.g. a combination of a throttle opening control and a fuel injection restoring control) for increasing the engine output irrespective of driver's accelerator operation. At the timing a reduction amount in an input shaft rotational speed Nt exceeds a predetermined value K after the ETC cooperative downshift control is started, it is presumed that the hydraulic pressure of a to-be-disengaged clutch is already reduced to a hydraulic pressure level equivalent to a predetermined transmission torque capacity that causes no undesirable acceleration or shock even if the engine output increasing control is started. And, under such assumption, the engine output increasing control is started at this timing. Accordingly, the present invention can accurately set the start timing of the engine output increasing control so as to suppress any undesirable acceleration or shock caused by the engine output increasing control.

Description

  The present invention relates to a control device for an automatic transmission that has improved downshift control technology that is executed based on the driver's intention to decelerate.

  Recent automatic transmissions for automobiles have a configuration in which a plurality of shift stages are achieved by changing the engagement state of a plurality of friction system engagement elements such as a hydraulic clutch and a brake by switching a hydraulic control circuit. However, in such an automatic transmission, if sufficient engine braking force cannot be obtained even when the accelerator is turned off due to a downhill or the like, the driver turns off the overdrive switch or shifts the shift lever from the D range. The engine braking force is increased by performing a downshift by switching to the S range or the L range.

  By the way, when the downshift for increasing the engine braking force is performed based on the driver's intention to decelerate (deceleration operation, etc.) in such an accelerator OFF state, the gear ratio of the automatic transmission is increased by the downshift. Therefore, it is necessary to increase the engine speed accordingly. However, in such an operation mode that requires engine braking, since the throttle valve is normally closed, torque transmission by the friction engagement element to achieve the shift stage after the downshift causes the output side to As the torque is transmitted to the engine side, the engine speed is increased. For this reason, the engine braking effect cannot be obtained at the necessary timing due to the longer shift time, or the inertia torque that accompanies the increase in engine rotation speed appears as the vehicle braking torque, temporarily increasing the engine braking force As a result, there is a problem that a shift shock occurs. Also, if the transmission torque of the friction engagement element is suddenly increased by hydraulic control of the automatic transmission or the like, the engine speed will rise rapidly and the shift time will be shortened, but the braking torque will suddenly increase and the shift shock will become even greater. End up.

  In order to solve such a problem, a control technique of Patent Document 1 (Japanese Patent No. 2924463) has been proposed. This switches between an engine output increasing means for temporarily increasing the engine output when the automatic transmission is downshifted to a low speed stage where the engine brake is applied when the accelerator is substantially OFF, and a hydraulic control circuit for example during the downshift. A timer that measures the elapsed time from a predetermined measurement start time, such as a shift output time point, and the slippage of the friction engagement element on the high-speed stage that is released during the downshift, The engine output by the engine output increasing means is based on the elapsed time measured by the timer so that the engine rotational speed increases until the low-speed stage friction engagement element that is engaged at the time is completely engaged. Increase control is started, and the start timing is determined when the friction engagement element is engaged, the release delay time, and the engine output increase delay The operating condition of the vehicle affecting at least one (specifically the oil temperature and the engine rotational speed in the hydraulic control circuit) has a configuration which is set based on.

Further, in Patent Document 1, there is a delay time until the frictional engagement element of the automatic transmission is actually released or engaged, and throttle opening control is performed to increase the engine output. After that, since there is a delay time until the engine output actually increases, setting the start timing in consideration of these delay times can reduce the shift time while suppressing the shift shock. Further, it is disclosed that it is desirable to control the opening of the throttle valve so that the engine blows up in accordance with the timing at which the friction engagement element on the high speed side starts to slip.
Japanese Patent No. 2924463 (first page to third page, etc.)

  However, the delay time until the frictional engagement element is actually released or engaged at the time of downshift is not only when the oil temperature in the hydraulic control circuit or the engine rotation speed but also when downshift control is executed. It also changes depending on the vehicle speed and the torque acting on the friction engagement element. In particular, during downshifts, the accelerator pedal is almost fully closed, so that any driving torque below the load / load (less than the torque required to drive at a constant speed at the current speed) must be applied from the engine side. In addition, it is also influenced by the operation state including during the slip control of the lockup clutch. Therefore, in setting the control start time based on the timer, even if the influence of the oil temperature and the engine rotational speed is taken into consideration, the throttle valve opening control (engine output increase control) cannot always be started at an appropriate timing. For this reason, there is a concern that the start timing of the throttle valve opening control deviates from an appropriate timing, and the driver feels an acceleration feeling or a shock due to the throttle valve opening control during the downshift. In addition, in order to properly set the timer reference value in consideration of the effects of oil temperature and engine speed, it is necessary to set a reference value based on repeated experiments in the conforming process, and specifications for transmission hydraulic pressure control Even if it becomes necessary to change the method of draining the hydraulic pressure due to the change, it is necessary to reset the reference value of the timer, which not only complicates the logic but also requires many parameter settings, and parameter adjustment work There is a problem that it takes a lot of time and effort.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to accurately set the start timing of the engine output increase control when performing a downshift based on the driver's intention to decelerate. Provided is a control device for an automatic transmission that can perform the engine output increase control with a simple logic configuration and a small parameter setting, without causing the driver to feel the acceleration and shock caused by the engine output increase control. There is.

According to the first aspect of the present invention, the hydraulic pressure applied to the plurality of friction engagement elements is individually controlled by the hydraulic pressure control means, whereby the engagement and release of each friction engagement element are selectively switched, and the transmission mechanism In a control device for an automatic transmission for switching a gear position, downshift control means for controlling hydraulic pressure so as to downshift the speed change mechanism to a gear speed at which an engine brake operates based on a driver's intention to decelerate, and the downshift control Engine output increase control means for executing engine output increase control for increasing the engine output regardless of the driver's accelerator operation, input shaft rotation speed detection means for detecting the input shaft rotation speed of the transmission mechanism, and the shift An output shaft rotational speed detecting means for detecting the output shaft rotational speed of the mechanism and a fuel cut executing means for executing a fuel cut, and starting engine output increase control; The timing, the input shaft rotational speed and the ratio of output shaft speed of said transmission mechanism (= gear ratio) is the first feature in that a time when falls below a predetermined value, further, the engine control computer the fuel cut start only when running fuel cut delay for delaying, starting the fuel cut from a state in which injecting downshift control start or et fuel, executing the fuel cut to the start timing of the engine output increase control This is a second feature.
In short, paying attention to the fact that the gear ratio (= input shaft rotational speed / output shaft rotational speed) decreases as the input shaft rotational speed of the speed change mechanism decreases after downshift control starts, and the gear ratio becomes a predetermined value after downshift control starts. When the pressure decreases to the following, it is determined that the hydraulic pressure of the disengagement friction engagement element has decreased below a predetermined transmission torque capacity equivalent hydraulic pressure that does not cause acceleration feeling or shock even when engine output increase control is started, The engine output increase control is started. As a result, the start timing of the engine output increase control can be set with high accuracy, and the driver does not feel the feeling of acceleration or shock due to the engine output increase control. Moreover, since the start timing of the engine output increase control can be set without depending on the timer as in Patent Document 1, the engine output increase control can be executed with a simple logic configuration and a small number of parameter settings, which is easy to put into practical use. There are also advantages.
Further, the invention according to claim 1, only when the engine control computer is running fuel cut delay for delaying the start of the fuel cut, the fuel cut from a state in which injecting downshift control start or al fuel The fuel cut is executed until the start timing of the engine output increase control , for the following reason.
If the engine control computer executes the fuel cut only when the fuel cut delay is being executed, the fuel cut delay may be applied when a small amount of fuel is injected to maintain the engine speed in the low speed range. When fuel is being injected with a request other than the above, it is possible to prevent the occurrence of a malfunction such as an engine stall by performing a fuel cut.
Further, as will be described later, when the fuel cut execution condition is satisfied when performing the downshift control, if the fuel cut is immediately started, a torque shock may occur. Therefore, the engine control computer starts the fuel cut. By executing a fuel cut delay that delays, torque shock is prevented. During this fuel cut delay, fuel is injected and engine torque is generated, but when the downshift control is started, the hydraulic pressure command value of the disengagement frictional engagement element is immediately lowered to or near its minimum value. If the transmission torque capacity of the frictional engagement element on the release side is immediately lost, torque shock will not occur even if fuel injection by fuel cut delay is immediately stopped and fuel cut is started. The input shaft rotation speed and gear ratio of the speed change mechanism can be reduced, and the start timing of the engine output increase control can be advanced so that the downshift speed can be advanced promptly.

Further, if the accelerator pedal is depressed even a little after the start of downshift control, the input shaft rotation speed is unlikely to decrease, and there is a possibility that the engine output increase control will not start.
As a countermeasure, as claimed in claim 2, the accelerator opening may be adapted to perform the fuel cut even when it is less than a predetermined value. In this way, even when the accelerator pedal is depressed a little after the start of the downshift control, the engine output increase control can be started by reducing the input shaft rotation speed by the fuel cut.

  By the way, if the fuel cut execution condition such as the accelerator fully closed is satisfied, if the fuel cut is started immediately, a torque shock may occur. As a countermeasure, the engine control computer prevents a torque shock by executing a fuel cut delay that delays the start of fuel cut. During fuel cut delay, fuel is injected and engine torque is generated. Therefore, if engine output increase control is started during fuel cut delay, the engine torque becomes too large and the vehicle may be accelerated.

As a countermeasure, as claimed in claim 3, the start timing of the engine output increase control, the input shaft rotational speed ratio between the output shaft rotational speed of the transmission mechanism in addition to the time when decreased to below a predetermined value, the engine control The engine output increase control may be prohibited during a period when it is determined that the computer is executing a fuel cut delay that delays the start of fuel cut. In this way, since it is possible to prevent the engine output increase control from being started during the fuel cut delay, it is possible to avoid the adverse effects caused by performing the engine output increase control during the fuel cut delay.
In this case, as in claim 4, as the difference between the engine rotational speed and the input shaft rotational speed is prohibited engine output increasing control when the downshift request is generated within a predetermined time from when a predetermined value or less May be. In short, it is judged that the fuel cut delay is in progress until the predetermined time has elapsed after the difference between the engine rotational speed and the input shaft rotational speed exceeds the predetermined value, and the engine output increase control is not performed. Is. In this way, it is possible to avoid the adverse effects of performing engine output increase control during fuel cut delay.

Alternatively, as described in claim 5 , the accelerator opening detecting means for detecting the accelerator opening is provided, and the engine output increases when a downshift request is generated within a predetermined time after the accelerator opening becomes equal to or less than a predetermined value. Control may be prohibited. In short, it is determined that the fuel cut delay is in progress until the predetermined time elapses after the accelerator opening becomes equal to or smaller than the predetermined value, and the engine output increase control is not performed. In this way, it is possible to avoid the adverse effects of performing engine output increase control during fuel cut delay.

According to a sixth aspect of the present invention, when the engine control computer is executing the fuel cut delay, information on the fuel cut delay is output from the engine control computer to the control computer of the automatic transmission, and the fuel cut delay is performed during the fuel cut delay. The engine output increase control may be prohibited when a downshift request is generated. In this way, the fuel cut delay information can be directly acquired from the engine control computer, and the engine output increase control during the fuel cut delay can be reliably prohibited.

Further, as in the seventh aspect , when the downshift control is started, the hydraulic pressure command value of the disengagement side frictional engagement element may be immediately lowered to or near the minimum hydraulic pressure. In this way, when the downshift control is started, the hydraulic pressure of the disengagement friction engagement element can be quickly reduced below the hydraulic pressure equivalent to the transmission torque capacity. The shift time can be shortened.

  Several embodiments embodying the best mode for carrying out the present invention will be described below.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the entire control system of the engine 11 which is an internal combustion engine will be described with reference to FIG. An air cleaner 13 is mounted on the upstream side of the intake pipe 12 of the engine 11, an air flow meter 14 for measuring the intake air amount Ga is installed on the downstream side thereof, and a throttle valve 15 is further provided on the downstream side thereof. . A motor 17 such as a DC motor is connected to the rotating shaft 15a of the throttle valve 15. The opening of the throttle valve 15 (throttle opening) is controlled by the driving force of the motor 17, and the throttle opening is controlled by the throttle opening. It is detected by the degree sensor 18.

  An injector 20 is attached to an intake manifold 19 that introduces intake air that has passed through the throttle valve 15 into each cylinder of the engine 11, and a spark plug 21 is attached to a cylinder head of each cylinder of the engine 11. A crank angle sensor 24 (engine rotation speed detecting means) is installed opposite to the outer periphery of the signal rotor 23 fitted to the crankshaft 22 of the engine 11, and an engine rotation speed signal Ne output from the crank angle sensor 24. The pulses are taken into the engine ECU 25 (engine control computer), and the engine rotation speed is detected by the pulse frequency of the engine rotation speed signal Ne.

  On the other hand, the depression amount (accelerator opening) of the accelerator pedal 26 is detected by an accelerator sensor 27 (accelerator opening detecting means), and a voltage signal Ap corresponding to the accelerator operation amount is sent to the electronic control unit 25 to the A / D converter 28. Is taken in through. Further, the intake air amount Ga detected by the air flow meter 14 and the voltage signals of the throttle opening TA detected by the throttle opening sensor 18 are also taken into the engine ECU 25 via the A / D converter 28.

  The engine ECU 25 is composed mainly of a microcomputer including a CPU 29, a ROM 30, a RAM 31, and the like, and controls various ignition control routines stored in the ROM 30 by the CPU 29, thereby controlling the ignition timing of the spark plug 21. At the same time, the pulse width of the injection signal applied to the injector 20 via the injector drive circuit 45 is controlled to control the fuel injection amount.

  Further, the engine ECU 25 executes various throttle control routines stored in the ROM 30 by the CPU 29 so that the throttle opening detected by the throttle opening sensor 18 matches the target throttle opening. The motor 17 of the throttle valve 15 is feedback-controlled by PID control or the like via the circuit 32. When the electronic throttle system is abnormal, the safety circuit 46 provided in the energization path from the motor drive circuit 32 to the motor 17 is activated, and the energization to the motor 17 is kept off. In this state, the throttle opening is held at a predetermined opening in order to enable retreat travel.

  Next, a schematic configuration of the automatic transmission 51 will be described with reference to FIGS. As shown in FIG. 3, an input shaft 53 of a torque converter 52 is connected to the output shaft of the engine 11, and a hydraulically driven transmission gear mechanism 55 (transmission mechanism) is connected to the output shaft 54 of the torque converter 52. Has been. Inside the torque converter 52, a pump impeller 71 and a turbine runner 72 constituting a fluid coupling are provided to face each other, and a stator 73 that rectifies the flow of oil is provided between the pump impeller 31 and the turbine runner 72. It has been. The pump impeller 71 is connected to the input shaft 53 of the torque converter 52, and the turbine runner 32 is connected to the output shaft 54 of the torque converter 52.

  The torque converter 52 is provided with a lockup clutch 56 for engaging or disengaging between the input shaft 53 side and the output shaft 54 side. The output torque of the engine is transmitted to the transmission gear mechanism 55 via the torque converter 52, is shifted by a plurality of gears (such as planetary gears) of the transmission gear mechanism 55, and is transmitted to the drive wheels (front wheels or rear wheels) of the vehicle. Is done.

  The transmission gear mechanism 55 is provided with a plurality of clutches C0, C1, C2 and brakes B0, B1, which are friction engagement elements for switching a plurality of shift stages. As shown in FIG. The gear ratio is switched by switching the engagement / release of C1 and C2 and the brakes B0 and B1 by hydraulic pressure and switching the combination of gears for transmitting power.

  FIG. 4 shows a combination of engagement of the clutches C0, C1, C2 and the brakes B0, B1 of the four-speed automatic transmission, and the mark “O” is held in the engaged state (torque transmission state) at the gear stage. The clutch and brake are shown, and the unmarked state shows the released state. For example, in the throttle depression state of the D range, as the vehicle speed increases, it is upshifted to first speed, second speed, third speed, and fourth speed. In the shift from the first speed to the second speed, B0 is released from the engagement of C0 and B0, and B1 is newly engaged. In the shift from the second speed to the third speed, B1 is released from the engagement of C0 and B1, and C2 is newly engaged. In the shift from the third speed to the fourth speed, C0 is released from the engagement of C0 and C2, and B1 is newly engaged.

  Here, for example, at the time of shifting from the second speed to the third speed, if B1 is fixed in the engaged state instead of being in a low pressure state for some reason, the interlock is generated by engaging C2. Therefore, a fail-safe mechanism is provided to prevent the drive wheels from stopping. Specifically, a hydraulic switch (not shown) is provided as a fail detection means for each clutch at a position where the hydraulic pressure acting on each clutch in the transmission gear mechanism 55 can be detected. This hydraulic switch is configured to be turned on (Hi output) when the actual hydraulic pressure is greater than or equal to the threshold value, and is turned off (Lo output) when the actual hydraulic pressure is less than the threshold value. By determining whether or not the relationship with the command value matches, an abnormal clutch is detected. Based on the detection result, control is performed so as not to shift to the gear position where the above interlock occurs.

  As shown in FIG. 2, the transmission gear mechanism 55 is provided with a hydraulic pump 58 driven by engine power, and a hydraulic control circuit 57 is provided in an oil pan (not shown) that stores hydraulic oil (oil). Is provided. The hydraulic control circuit 57 includes a line pressure control circuit 59, an automatic transmission control circuit 60, a lock-up control circuit 61, a manual switching valve 66, and the like. The hydraulic oil pumped up from the oil pan by the hydraulic pump 58 is controlled by the line pressure. This is supplied to the automatic transmission control circuit 60 and the lockup control circuit 61 via the circuit 59. The line pressure control circuit 59 is provided with a hydraulic pressure control valve (not shown) for controlling the hydraulic pressure from the hydraulic pump 58 to a predetermined line pressure. The automatic transmission control circuit 60 includes a transmission gear mechanism. A plurality of shift hydraulic control valves (hydraulic control means) for controlling the hydraulic pressure supplied to the respective clutches C0, C1, C2 and the brakes B0, B1 are provided. The lockup control circuit 61 is provided with a lockup control hydraulic control valve (not shown) for controlling the hydraulic pressure supplied to the lockup clutch 56.

  Each hydraulic control valve is constituted by, for example, a linear solenoid valve, and controls the hydraulic pressure by a suction force generated by a flowing current by applying a voltage with a predetermined duty. For this reason, the current of the hydraulic control valve and the hydraulic pressure are closely related, and the hydraulic pressure is controlled by controlling the current value. Further, in order to absorb the variation of the current value with respect to the duty, the current value is monitored by a current detection means (not shown) of an automatic transmission electronic control circuit (hereinafter referred to as “AT-ECU”) 70 and the current value is feedback-controlled. I am doing so.

  Further, a manual switching valve 66 that is switched in conjunction with the operation of the shift lever 65 is provided between the line pressure control circuit 59 and the automatic transmission control circuit 60. When the shift lever 65 is operated to the neutral range (N range) or the parking range (P range), even if the energization of the hydraulic control valve of the automatic transmission control circuit 60 is stopped (OFF), The hydraulic pressure supplied to the transmission gear mechanism 55 is switched by the manual switching valve 66 so that the transmission gear mechanism 55 is in a neutral state.

  On the other hand, the transmission gear mechanism 55 includes an input shaft rotation speed sensor 68 (input shaft rotation speed detection means) that detects an input shaft rotation speed Nt (output shaft rotation speed of the torque converter 52) of the transmission gear mechanism 55, and a transmission gear. An output shaft rotation speed sensor 69 (output shaft rotation speed detection means) for detecting the output shaft rotation speed No of the mechanism 55 is provided.

  Output signals from these various sensors are input to the AT-ECU 70. The AT-ECU 70 is mainly composed of a microcomputer, and by executing each routine stored in a built-in ROM (storage medium), the transmission gear mechanism 55 shifts according to a preset shift pattern of FIG. As is done, the energization of each hydraulic control valve of the automatic transmission control circuit 60 is controlled according to the operating position of the shift lever 65 and the operating conditions (throttle opening, vehicle speed, etc.), and each clutch of the transmission gear mechanism 55 is controlled. By controlling the hydraulic pressure applied to C0, C1, C2 and each brake B0, B1, as shown in FIG. 4, the engagement / release of each clutch C0, C1, C2 and each brake B0, B1 is switched, The gear ratio of the transmission gear mechanism 55 is switched by switching the combination of gears that transmit power.

  At this time, when performing the downshift, the AT-ECU 70 performs control as shown in FIGS. In the following description, the clutches C0, C1, C2 and the brakes B0, B1 are collectively referred to simply as “clutch”. Further, a clutch that switches from an engaged state to a released state during downshift control is referred to as a “release side clutch”, and a clutch that switches from a released state to an engaged state is referred to as an “engagement side clutch”.

  FIG. 6 is a time chart showing a control example of “power-on downshift” in which the driver depresses the accelerator pedal 26 and downshifts, and FIG. 7 is for generating an engine brake based on the driver's intention to decelerate. 7 is a time chart showing a control example of “ETC cooperative downshift” in which engine output increase control is executed during downshift of the engine.

First, an example of power-on downshift control will be described with reference to FIG.
When the driver depresses the accelerator pedal 26 greatly and the throttle opening is suddenly released, it is determined as a power-on downshift, and a downshift gear shift command is output. At this time point t0, the hydraulic pressure command value for the release side clutch is lowered to the initial hydraulic pressure, and then the hydraulic pressure command value for the release side clutch is lowered with a constant gradient. As a result, the engagement force of the release side clutch is reduced and the engine load is reduced, so that the input shaft rotation speed Nt of the transmission gear mechanism 55 (the output shaft rotation speed of the torque converter 52) starts to increase.

  In addition, the hydraulic pressure command value of the engagement side clutch is set to a predetermined charging hydraulic pressure Po so that the engagement side clutch is in a state immediately before the engagement force is generated at the time t0 when the downshift gear shift command is output. Then, filling control for filling the engagement side clutch with hydraulic oil is executed. At the time t1 when this filling control is executed for a predetermined time tF and the engaging clutch is in a state immediately before the engagement force is generated, the hydraulic pressure command value of the engaging clutch is reduced to the standby oil pressure PtAp to perform the filling control. finish. Thereafter, the standby hydraulic pressure PtAp holds the state immediately before the engagement side clutch generates the engagement force. This standby hydraulic pressure PtAp is set near the set load equivalent hydraulic pressure PsAp of the return spring of the engagement side clutch.

  Thereafter, at the time t2 when the rising of the input shaft rotational speed Nt (Nt change rate ≧ determination value) is detected, the hydraulic pressure of the disengagement side clutch is feedback controlled so that the rising gradient of the input shaft rotational speed Nt becomes a predetermined value. To do. During this feedback control, the hydraulic pressure command value of the disengagement side clutch is slightly higher than the set spring equivalent hydraulic pressure PsDr of the return spring. Then, the shift progress rate SftR [= 100 × (input shaft rotational speed Nt−output shaft rotational speed No × pre-shift gear ratio) / (output shaft rotational speed No × post-shift gear ratio−output shaft rotational speed No × pre-shift gear) At the time t3 when the ratio)] reaches the predetermined value B, control for increasing the hydraulic pressure command value of the engaging clutch with a constant gradient is started. After that, at the time t4 when the shift progress rate SftR reaches the predetermined value A, the hydraulic pressure command value for the disengagement side clutch is decreased at a constant gradient.

  At time t5 when the shift progress rate SftR reaches a predetermined value C, the hydraulic pressure command value for the engagement side clutch is set to the maximum pressure, and the hydraulic pressure for the engagement side clutch is increased to the maximum pressure. By controlling in this way, the engagement force of the engagement side clutch is increased in accordance with the timing at which the input shaft rotation speed Nt increases to the rotation speed corresponding to the low speed stage of the downshift destination, and the downshift is completed.

  Next, an example of ETC cooperative downshift control will be described with reference to FIG. At the time point t0 when the ETC cooperative downshift execution condition is established and the downshift gear shift command is output, the hydraulic pressure command value of the disengagement side clutch is immediately reduced to the minimum hydraulic pressure (0 kPa) or the vicinity thereof. As a result, the hydraulic pressure of the disengagement side clutch is quickly reduced below the hydraulic pressure corresponding to the transmission torque capacity.

  Also in this ETC cooperative downshift, the hydraulic pressure control of the engagement side clutch is almost the same as the power-on downshift, and at the time t0 when the downshift gear shift command is output, the hydraulic pressure command value of the engagement side clutch is set to a predetermined value. The charging control for charging the engagement side clutch with hydraulic oil is executed. When this charging control is executed for a predetermined time tF and the state immediately before the engagement side clutch generates engagement force, the hydraulic pressure command value of the engagement side clutch is changed to the standby oil pressure PtAp (return spring of the engagement side clutch). To the set load equivalent hydraulic pressure PsAp) to finish the filling control. Thereafter, the engagement side clutch holds the engagement force in a state where a desired emblem is generated by the standby hydraulic pressure PtAp by the engagement clutch. Subsequent pressure increase control is performed in the same manner as the power-on downshift described above.

  The feature of this ETC cooperative downshift is that the engine output increase control is executed as follows. In the process in which the actual hydraulic pressure of the release side clutch decreases to the minimum hydraulic pressure (0), the transmission torque capacity of the release side clutch decreases, and the input shaft rotational speed Nt of the transmission gear mechanism 55 decreases. As a result, even when the decrease amount ΔNt of the input shaft rotational speed Nt from the start of the ETC cooperative downshift control becomes equal to or higher than the set value K, even if the hydraulic pressure of the release side clutch starts the engine output increase control, the acceleration feeling If it is determined that the hydraulic pressure has fallen below the predetermined transmission torque capacity equivalent pressure that does not cause a shock, engine output increase control is started.

  At this time, the throttle opening command value is set to a predetermined throttle opening command value and throttle opening control is started, and the fuel cut flag (hereinafter referred to as “F / C flag”) is turned OFF to return to fuel injection. Control is started and fuel injection is resumed.

  The engine output increases with a predetermined delay from the start of the engine output increase control (throttle opening control and fuel injection return control). As a factor that delays the increase in engine output, regarding throttle opening control, the response delay (Ta) of the valve opening operation of the throttle valve 15 and the response delay from when the throttle valve 15 is actually opened until the engine output increases ( Tb), and regarding the fuel injection return control, there is a response delay (Tc) from when the fuel injection is restarted until the engine output increases.

  After the start of the throttle opening control (engine output increase control), a throttle opening command value set so as to achieve an input shaft rotational speed Nt behavior that realizes a desired shift time and shift feeling is output and held. The throttle opening command value detects parameters (shift pattern [gear ratio change], cooling water temperature, input shaft rotational speed Nt, etc.) that affect the friction loss of the engine 11 and the amount of change in the input shaft rotational speed Nt before and after the shift. It is set based on the result and the desired shift time. Furthermore, if the throttle opening command value is changed depending on the road surface gradient and the deceleration of the vehicle body, the feeling can be adjusted to a desired state in detail. The throttle opening command value is corrected by the output of the air flow meter 14. By this engine output increase control, the input shaft rotation speed Nt of the transmission gear mechanism 55 (the output shaft rotation speed of the torque converter 52) starts to increase.

  During the execution of the engine output increase control, an end for ending the actual engine output increase by the engine output increase control in accordance with the time when the downshift is finally ended (the time when the shift progress rate SftR becomes 100%). A predetermined amount of engine output increase is held while making a determination. This end determination takes into account the response delay until the engine output actually stops from the end command based on the shift progress rate SftR and the change amount ΔSftR per unit time ΔT of the shift progress rate, and cancels this response delay. The possible control end timing is calculated as to when the shift progress rate SftR is reached, and whether the shift progress rate SftR exceeds the calculated value or not, throttle opening control and fuel injection that are engine output increase control The end time (t8, t9) of the return control is determined. As a result, when it is determined that the end time (t8, t9) is reached, in the throttle opening control, the end control is performed in order to attenuate the throttle opening command value to "0". In this end control, the throttle opening control command value is attenuated to “0” with a predetermined gradient in order to ensure the transient reproducibility of the electronic throttle. As for the fuel injection return control, the fuel cut is restarted by returning the F / C flag to ON according to the end determination. However, this is not the case when the fuel cut request from the engine 11 side is extinguished due to a rapid decrease in engine speed or other causes.

  Regarding the throttle opening control as a factor of the engine output increase end response delay, the response delay (Td) of the fully closing operation of the throttle valve 15 and until the engine output actually increases after the throttle valve 15 is actually fully closed. Response delay (Te) and a time (Tsd) from the end determination until the throttle opening command value is attenuated to “0”. Further, regarding the fuel injection return control, there is a response delay (Tf) from when the fuel cut is restarted until the engine output disappears.

  Here, the response delay (Td) of the closing operation of the throttle valve 15 is calculated from a map of parameters (cooling water temperature, battery voltage, etc.) related to the drive response of the motor 17 of the electronic throttle system. The response delay (Te) from when the throttle valve 15 is fully closed until the engine output stops increasing is a delay from when the intake air reduced by the throttle valve 15 being fully closed is sucked into the cylinder until combustion occurs. , And a map of parameters related to the intake flow velocity (engine speed, throttle opening, etc.). The time (Tsd) from the end determination until the throttle opening command value is attenuated to “0” is calculated from the throttle opening command value / attenuation gradient. The response delay (Tf) from when the fuel cut is restarted until the engine output disappears is the time from when the fuel cut is restarted until the cylinder where the fuel cut is performed reaches the combustion stroke (the crankshaft rotates by 720 ° C.). Is set by the time T720 ° C. A) required for the above.

  The shift control of the first embodiment described above is executed according to the following routines in cooperation between the AT-ECU 70 and the engine ECU 25. The processing contents of these routines will be described below.

[Shift control]
The shift control routine of FIG. 8 is a main routine of shift control that is executed at predetermined time intervals (for example, every 8 to 32 msec) during engine operation. When this routine is started, it is first determined in step 100 whether or not a shift is necessary (whether or not a shift command is output). If no shift is necessary, this routine is performed without performing the subsequent processing. Exit.

  On the other hand, if a shift is necessary, the routine proceeds to step 101, where a shift type determination routine of FIG. 9 described later is executed to determine the shift type corresponding to the current shift command. Thereafter, the process proceeds to step 102, where it is determined whether or not the ETC cooperative downshift execution flag xEtc is set to ON, which means that the ETC cooperative downshift execution condition is satisfied, and the ETC cooperative downshift execution flag xEtc is set to OFF. If YES, the routine proceeds to step 105, where a shift hydraulic pressure control routine (not shown) corresponding to the shift type is executed, the gear is shifted to the shift stage corresponding to the current shift command, and this routine is terminated.

  On the other hand, if the ETC cooperative downshift execution flag xEtc is set to ON, it is determined that the ETC cooperative downshift execution condition is satisfied, the process proceeds from step 102 to step 103, and the throttle opening control routine of FIG. And the throttle opening control is executed. In the next step 104, a fuel injection return control routine of FIG. 19 described later is started to execute the fuel injection return control. Thereafter, the routine proceeds to step 105, where a shift hydraulic pressure control routine shown in FIG. 10 to be described later is executed to shift to a gear position corresponding to the current shift command, and this routine is terminated.

[Transmission type judgment]
The shift type determination routine of FIG. 9 is a subroutine executed in step 101 of the shift control routine of FIG. When this routine is started, first, at step 111, it is determined whether the current shift command is an upshift or a downshift. If it is determined to be an upshift, the routine proceeds to step 112, where the load state applied to the automatic transmission 51 is determined. It is determined whether the power is on (a state where the automatic transmission 51 is driven from the engine 11 side) or the power is off (a state where the automatic transmission 51 is driven from the driving wheel side). Based on the determination result, it is determined whether the shift type corresponding to the current shift command corresponds to a power-on upshift (step 118) or a power-off upshift (step 119).

  On the other hand, if it is determined in step 111 that the vehicle is downshifted, the process proceeds to step 113 to determine whether the load applied to the automatic transmission 51 is power-on or power-off. It is determined whether or not the downshift is due to the person's intention to decelerate. Here, in the case of either a select shift by the operation of the shift lever 16 or a sport shift by an operation of the switch mounted on the steering part or the shift lever 16 in the manual mode, it is determined that the downshift is due to the driver's intention to decelerate. If it is determined that the downshift is due to the driver's intention to decelerate, the process proceeds to step 116 to determine whether or not the ETC cooperative downshift execution condition is satisfied. It is determined whether or not the temperature range has a good reproducibility of the hydraulic response to the command value. As a result, when it is determined that the ETC cooperative downshift execution condition is satisfied, the process proceeds to step 117, the ETC cooperative downshift execution flag xEtc is set to ON, and then the process proceeds to step 121, where the current shift type Is determined as an ETC cooperative downshift.

  If it is determined in step 115 that the downshift is not due to the driver's intention to decelerate, or if it is determined in step 116 that the ETC cooperative downshift execution condition is not satisfied, the routine proceeds to step 122, where The type is determined as a power-off downshift.

  On the other hand, if it is determined in step 113 that the power is on, the process proceeds to step 114 in order to distinguish between power on by ETC cooperative downshift control (engine output increase control) and power on by depression of the accelerator pedal 26. Then, it is determined whether or not the ETC cooperative downshift execution flag xEtc is set to ON. If it is set to ON, the process proceeds to step 121, where the current shift type is determined to be ETC cooperative downshift, and ETC cooperation is determined. If the downshift execution flag xEtc is set to OFF, the routine proceeds to step 120, where it is determined that the current shift type is a power-on downshift.

[Speed change hydraulic control]
The shift hydraulic pressure control routine of FIG. 10 is executed when the shift type is ETC cooperative downshift, and serves as a downshift control means in the claims. When this routine is started, first, in step 130, an engine output increase control prohibition determination routine shown in FIG. 18, which will be described later, is executed to determine whether or not engine output increase control is prohibited. 11 is executed to control the hydraulic pressure of the release side clutch, and in the next step 132, an engagement side clutch hydraulic pressure control routine shown in FIG. Controls the hydraulic pressure of the engaging clutch.

  Thereafter, the process proceeds to step 133, and it is determined whether or not the downshift is completed based on whether or not a control stage flag Flag1 = 4 and Flag2 = 5 described later. Then, when the downshift is completed, the process proceeds to step 134 where both the control stage flags Flag1 and Flag2 are reset to the initial value “0”, and the other flags xEtc, xEtcTSt, xEtcFSt, xEtcTEd, xEtcFEd are all “OFF”. To end the routine.

[Release side clutch hydraulic control]
Next, the processing content of the release side clutch hydraulic pressure control routine of FIG. 11 executed in step 131 of the transmission hydraulic pressure control routine of FIG. 10 will be described. When this routine is started, first, in step 140, it is determined whether or not the current shift type is ETC cooperative downshift based on whether or not the ETC cooperative downshift execution flag xEtc is set to ON. If the ETC cooperative downshift execution flag xEtc is set to ON, the routine proceeds to step 141 where the hydraulic pressure command value of the disengagement side clutch is immediately reduced to 0 [kPa] which is the minimum hydraulic pressure (see FIG. 7). The processing in step 141 also serves as downshift control means in the claims.

  On the other hand, if it is determined in step 140 that the ETC cooperative downshift execution flag xEtc is OFF, the process proceeds to step 142, and the current value depends on whether the value of the control stage flag Flag1 is 0-3. The release side clutch hydraulic pressure control stage is determined. This control stage flag Flag1 is a flag that is incremented by 1 every time it proceeds to each stage of the release side clutch hydraulic pressure control. The initial value is 0 and the maximum value is 4. Accordingly, the release side clutch hydraulic pressure control is a four-step sequence control.

  Since the control stage flag Flag1 is set to the initial value (0) at the time point t0 when the release side clutch hydraulic pressure control is started, the process proceeds to step 143, the control stage flag Flag1 is set to “1”, and the next step Proceeding to 144, the hydraulic pressure command value of the release side clutch is set to the standby hydraulic pressure PtDr, and the hydraulic pressure supplied to the release side clutch is reduced to the standby hydraulic pressure PtDr (first stage control).

  At the next start of this routine, since Flag1 is already 1, the process proceeds to step 145, where the hydraulic pressure of the disengagement side clutch is held at the standby hydraulic pressure PtDr, and in the next step 146, the shift progress rate SftR is set to 100% It is determined whether or not the predetermined value A has been reached. If the predetermined value A has not been reached, the present routine is terminated. Thereafter, when the shift progress rate SftR reaches a predetermined value A, the process proceeds to step 147, the control stage flag Flag1 is set to “2”, the second stage control is terminated, and the third stage control is performed. Transition.

  In this third-stage control, first, in step 148, the hydraulic pressure command value for the disengagement side clutch is decreased at a constant gradient. Then, in the next step 149, it is determined whether or not the release side hydraulic pressure command value has decreased to 0 or less, and this third stage of control (until the release side hydraulic pressure command value has decreased to 0 or less) ( Continue hydraulic pressure reduction control. Thereafter, when the hydraulic pressure command value of the release side clutch is reduced to the minimum value (0 or less), the process proceeds to step 150, the control stage flag Flag1 is set to “3”, and the control of the third stage is terminated. The process proceeds to the fourth stage control.

  In the control of the fourth stage, first, in step 151, the hydraulic pressure command value of the release side clutch is set to 0, and the release side clutch is maintained in a completely released state. Then, in the next step 152, the control stage flag Flag1 is set to “4”, and the release side clutch hydraulic pressure control is terminated.

[Engagement side clutch hydraulic control]
The engagement side clutch hydraulic pressure control routine of FIG. 12 is a subroutine executed in step 132 of the shift hydraulic pressure control routine of FIG. When this routine is started, first, in step 161, the current stage of clutch clutch hydraulic pressure control is determined based on whether the value of the control stage flag Flag2 is 0 to 4. The control stage flag Flag2 is a flag that increases by 1 each time the process proceeds to each stage of the engagement side clutch hydraulic pressure control. The initial value is 0 and the maximum value is 5. Therefore, the clutch clutch hydraulic pressure control is a five-step sequence control.

  At the time point t0 when the engagement side clutch hydraulic pressure control is started, the control stage flag Flag2 is set to the initial value (0), so the routine proceeds to step 162, where the state immediately before the engagement side clutch generates the engagement force. In this way, the hydraulic pressure command value for the engaging side clutch is set to a predetermined charging hydraulic pressure Po, and the charging control for filling the engaging side clutch with hydraulic oil is executed. Then, in the next step 163, the control stage flag Flag2 is set to “1”, and then the process proceeds to step 164, the timer t for counting the filling control time is reset to 0, and this routine is finished.

  At the next startup of this routine, since Flag2 = 1 is already set, the process proceeds to step 165, the filling control time timer t is counted up, the filling control time up to the present is counted, and in the next step 166, It is determined whether or not the value of the charging control time timer t has become equal to or greater than the predetermined time tF. Until the charging control time reaches the predetermined time tF, the hydraulic pressure command value of the engagement side clutch is held at the charging hydraulic pressure Po, The filling control is continued (step 169).

  Here, the predetermined time tF is a time required for the engagement side clutch to be in a state immediately before the engagement force is generated by the filling control, and is set in advance by an experiment or a simulation.

  Thereafter, when the filling control time reaches the predetermined time tF (when the engagement clutch is brought into a state immediately before generating the engagement force by the filling control), the routine proceeds to step 167 and the control stage flag Flag2 is set to “2”. In the next step 168, the hydraulic pressure command value of the engagement side clutch is lowered to the standby hydraulic pressure PtAp, and the filling control is finished. Thereafter, the standby hydraulic pressure PtAp holds the state immediately before the engagement side clutch generates the engagement force.

  When the hydraulic pressure of the engagement side clutch is controlled to the standby hydraulic pressure PtAp, since the control stage flag Flag2 is “2”, the routine proceeds to step 170, and the shift progress rate SftR becomes the predetermined value D (see FIG. 7). It is determined whether or not it has been reached, and the hydraulic pressure command value of the engagement side clutch is held at the standby hydraulic pressure PtAp until the shift progress rate SftR reaches the predetermined value D (step 173).

  Thereafter, when the shift progress rate SftR reaches the predetermined value D, the routine proceeds to step 171, where the control stage flag Flag 2 is set to “3”, and in the next step 172, the hydraulic pressure command value of the engagement side clutch is set to a constant gradient. Shift to control to increase in.

  Thereafter, when this routine is started, since the control stage flag Flag2 is “3”, the routine proceeds to step 174, where it is determined whether or not the shift progress rate SftR has reached a predetermined value G close to 100%. Until the shift progress rate SftR reaches the predetermined value G, the control to increase the hydraulic pressure command value of the engagement side clutch with a constant gradient is continued (step 177).

  Thereafter, when the shift progress rate SftR reaches the predetermined value G, the process proceeds to step 175, the control stage flag Flag2 is set to “4”, and in the next step 176, the hydraulic pressure command value of the engagement side clutch is set to the maximum pressure. To increase the hydraulic pressure of the engagement side clutch to the maximum pressure. By controlling in this manner, the downshift is completed by increasing the engagement force of the engagement side clutch in accordance with the timing at which the input shaft rotation speed Nt increases to the rotation speed corresponding to the low speed stage of the downshift destination.

  Thereafter, when this routine is started, since the control stage flag Flag2 is “4”, the process proceeds to step 178, and whether a predetermined time has elapsed since the control stage flag Flag2 was set to “4”. (That is, whether or not a predetermined time has elapsed since the shift progress rate SftR has reached the predetermined value G). When the predetermined time has elapsed, the routine proceeds to step 179, where the control stage flag Flag2 is set to “5”. The engagement side clutch hydraulic pressure control is terminated.

[Throttle opening control]
The throttle opening control routine of FIG. 13 is a subroutine executed in step 103 of the shift control routine of FIG. 8, and serves as engine output increase control means in the claims.

  When this routine is started, first, at step 201, it is determined whether or not the throttle opening control start flag xEtcTSt is OFF which means before the opening of the throttle opening control. If it is OFF, the routine proceeds to step 203, which will be described later. The throttle opening control start determination routine shown in FIG. 14 is executed to determine whether it is the start timing of throttle opening control, and the throttle opening control start flag xEtcTSt is set / reset according to the determination result.

  After this, the routine proceeds to step 205, where it is determined whether or not the throttle opening control start flag xEtcTSt remains OFF. If it remains OFF, the routine proceeds to step 207 where the intake air amount before the throttle opening control is started is determined. The stored value GaB is updated with the current detected value Ga of the air flow meter 14, and this routine is terminated.

  On the other hand, if it is determined in step 205 that the throttle opening control start flag xEtcTSt is set to ON, the routine proceeds to step 209, where the throttle opening command value tangleat (throttle opening amount) is set to the throttle opening in FIG. Using the amount setting map, the speed is set in accordance with the downshift speed, the water temperature, and the input shaft rotation speed Nt. Thereafter, the process proceeds to step 210, a throttle opening amount correction control routine of FIG. 16 described later is executed, and this routine is terminated.

  If it is determined in step 201 that the throttle opening control start flag xEtcTSt is ON, meaning that the throttle opening control is being executed, the routine proceeds to step 202, where the throttle opening control end flag xEtcTEd is set for the throttle opening control. It is determined whether or not it means OFF before the end, and if it is OFF, the process proceeds to step 204 to execute a throttle opening control end determination routine of FIG. It is determined whether or not, and the throttle opening control end flag xEtcTEd is set / reset according to the determination result.

  Thereafter, the process proceeds to step 206, where it is determined whether or not the throttle opening control end flag xEtcTEd remains OFF. If it remains OFF, the processes of steps 209 and 210 are executed to perform the throttle opening control. continue.

  On the other hand, if it is determined in step 206 that the throttle opening control end flag xEtcTEd is set to ON, the process proceeds to step 208, in which the throttle opening command value tangleat is corrected by a predetermined amount dtangleat to reduce the throttle. An end control for attenuating the opening command value tangleat to “0” with a predetermined gradient is executed.

[Throttle opening control start judgment]
The throttle opening control start determination routine of FIG. 14 is a subroutine executed in step 203 of the throttle opening control routine of FIG. When this routine is started, first, at step 221, it is determined whether or not the reduction amount ΔNt of the input shaft rotational speed Nt from the start of the ETC cooperative downshift control is equal to or greater than the set value K, and the input shaft rotational speed Nt is still set. If the amount of decrease ΔNt is not equal to or greater than the set value K, it is determined that the engine output increase control start timing has not been reached, and this routine is immediately terminated.

  Thereafter, when the decrease amount ΔNt of the input shaft rotation speed Nt from the start of the ETC cooperative downshift control becomes equal to or greater than the set value K, it is determined that the start timing of the engine output increase control has been reached, and the steps 221 to 222 are performed. Then, the throttle opening control start flag xEtcTSt is set to ON.

[Throttle opening control end judgment]
The throttle opening control end determination routine of FIG. 15 is a subroutine executed in step 204 of the throttle opening control routine of FIG. When this routine is started, first, at step 241, the response delay (Td) of the fully closed operation of the throttle valve 15 and the response delay from when the throttle valve 15 is actually fully closed until there is no actual increase in engine output. (Te) and a time (Tsd) from the end determination until the throttle opening command value is attenuated to “0” are calculated. Here, the response delay (Td) of the closing operation of the throttle valve 15 is calculated from a map of parameters (cooling water temperature, battery voltage, etc.) related to the drive response of the motor 17 of the electronic throttle system. The response delay (Te) from when the throttle valve 15 is fully closed until the engine output stops increasing is a delay from when the intake air reduced by the throttle valve 15 being fully closed is sucked into the cylinder until combustion occurs. , And a map of parameters related to the intake flow velocity (engine speed, throttle opening, etc.). The time (Tsd) from the end determination until the throttle opening command value is attenuated to “0” is calculated from the throttle opening command value / attenuation gradient.

Thereafter, the process proceeds to step 242, and the shift progress rate SftRed at the end of the throttle opening control (at the start of the end control) is calculated by the following equation.
SftRed = 100−DSftR × (Td + Te + Tsd) / tsmp
Here, DSftR is the amount of change per calculation cycle of the shift progress rate SftR (current value of SftR−previous value), and tsmp is the calculation cycle of DSftR.

  Thereafter, the routine proceeds to step 243, where it is determined whether or not the current shift progress rate SftR is equal to or greater than the SftRed. If the shift progress rate SftR has not yet reached the SftRed, this routine is terminated. When the shift progress rate SftR reaches SftRed, the process proceeds to step 244, where the throttle opening control end flag xEtcTEd is set to ON.

[Throttle opening amount correction control]
The throttle opening amount correction control routine of FIG. 16 is a subroutine executed in step 210 of the throttle opening control routine of FIG. When this routine is started, first, at step 251, it is determined whether or not an execution condition for throttle opening amount correction control is satisfied. This execution condition is determined based on, for example, whether the elapsed time from the throttle opening command is equal to or longer than the response delay equivalent time. If the elapsed time from the throttle opening command is less than the response delay equivalent time, the throttle opening amount The execution condition of the correction control is not satisfied, and this routine is finished as it is. Thereafter, when the elapsed time from the throttle opening command becomes equal to or longer than the response delay equivalent time, the execution condition of the throttle opening amount correction control is established, and the routine proceeds to step 252, where the throttle opening command value tangleat (throttle opening amount) is set. Correct by the following formula.
tangleat = tangleat × DGaT / (Ga—GaB)

  Here, DGaT is an increase target value by throttle opening control of the intake air amount Ga, and is set by a table or the like according to the throttle opening command value tangleat. GaB is the intake air amount immediately before the start of the throttle opening control stored in step 207 of the throttle opening control routine of FIG. By correcting the throttle opening command value tangleat (throttle opening amount) using the above equation, system manufacturing variations, variations due to changes over time, and variations due to operating conditions such as atmospheric pressure and intake air temperature are corrected.

[Engine output increase control prohibition judgment]
The engine output increase control prohibition determination routine of FIG. 18 is a subroutine executed in step 130 of the transmission hydraulic pressure control routine of FIG. When this routine is started, first, at step 261, it is determined whether or not the accelerator opening detected by the accelerator sensor 27 is equal to or smaller than a set value. If the accelerator opening is equal to or smaller than the set value, the routine proceeds to step 264. Then, the ETC cooperative downshift execution flag xEtc is set to OFF to prohibit engine output increase control (throttle opening control and fuel injection return control).

  On the other hand, if the accelerator opening is larger than the set value, the process proceeds from step 261 to step 262, where it is determined whether the oil temperature is equal to or higher than the set value, and if the oil temperature is equal to or higher than the set value, the process proceeds to step 264. Then, the ETC cooperative downshift execution flag xEtc is set to OFF to prohibit engine output increase control (throttle opening control and fuel injection return control).

  On the other hand, if the oil temperature is lower than the set value, the process proceeds from step 261 to step 262, and the predetermined value is reached after the difference (Ne−Nt) between the engine speed Ne and the input shaft speed Nt becomes equal to or greater than the set value. It is determined whether or not the fuel cut delay is being performed depending on whether or not it is within the time. If it is determined that the fuel cut delay is being performed, the process proceeds to step 264 to set the ETC cooperative downshift execution flag xEtc to OFF. The engine output increase control (throttle opening control and fuel injection return control) is prohibited.

  If any of the above steps 261 to 263 is determined as “No”, this routine is terminated without doing anything. In this case, engine output increase control (throttle opening control and fuel injection return control) is permitted.

[Fuel injection return control]
The fuel injection return control routine of FIG. 19 is a subroutine executed in step 104 of the shift control routine of FIG. 8, and serves as engine output increase control means in the claims. When this routine is started, first, in step 300, it is determined whether or not a fuel cut request is generated on the engine control side based on the fuel cut information transmitted from the engine ECU 25 to the AT-ECU 70, and the fuel cut is performed. If no request has occurred, the process proceeds to step 307 and fuel injection is continued.

  On the other hand, if it is determined in step 300 that a fuel cut request has been generated (fuel cut is in progress), the routine proceeds to step 301 where the fuel injection return control start flag xEtcFSt is set before the start of the fuel injection return control. It is determined whether or not it is OFF, and if it is OFF, the process proceeds to step 303 to execute a fuel injection start determination routine of FIG. 20 described later to determine whether or not it is the start timing of fuel injection return control. The fuel injection return control start flag xEtcFSt is set / reset according to the determination result.

  After this, the routine proceeds to step 305, where it is determined whether or not the fuel injection return control start flag xEtcFSt remains OFF. If it remains OFF, this routine is terminated, but it is determined that it has been set to ON. If so, the process proceeds to step 308 to perform fuel injection.

  If it is determined in step 301 that the fuel injection return control start flag xEtcFSt is ON, meaning that the fuel injection return control is being executed, the routine proceeds to step 302 where the fuel injection return control end flag xEtcFEd is It is determined whether or not it means OFF before the end of the injection return control. If it is OFF, the routine proceeds to step 304, where a fuel injection return control end determination routine of FIG. Is determined, and the fuel injection return control end flag xEtcFEd is set / reset according to the determination result.

  Thereafter, the process proceeds to step 306, where it is determined whether or not the fuel injection return control end flag xEtcFEd remains OFF. If it remains OFF, the process proceeds to step 308 and fuel injection is performed.

  If it is determined in step 306 that the fuel injection return control end flag xEtcFEd is ON, which means the end of the fuel injection return control, the process proceeds to step 309 to restart the fuel cut.

[Fuel injection start judgment]
The fuel injection start determination routine of FIG. 20 is a subroutine executed in step 303 of the fuel injection return control routine of FIG. When this routine is started, first, at step 321, it is determined based on the fuel cut information transmitted from the engine ECU 25 to the AT-ECU 70 whether the F / C flag (fuel cut flag) is OFF, If the F / C flag is OFF, the routine proceeds to step 322, where the fuel injection return control start flag xEtcFSt is set to ON, and this routine ends. On the other hand, if it is determined in step 321 that the F / C flag is ON, this routine is terminated as it is.

[Fuel injection end determination]
The fuel injection end determination routine of FIG. 21 is a subroutine executed in step 304 of the fuel injection return control routine of FIG. When this routine is started, first, at step 341, a response delay (Tf) from when the fuel cut is restarted until the engine output is lost is calculated. At this time, a time T720 ° C. A required for the crankshaft to rotate at 720 ° C. A is calculated as a response delay (Tf).

Thereafter, the process proceeds to step 342, and the shift progress rate SftRed at the end of the fuel injection return control (at the start of the end control) is calculated by the following equation.
SftRed = 100−DSftR × Tf / tsmp
Here, DSftR is the amount of change per calculation cycle of the shift progress rate SftR (current value of SftR−previous value), and tsmp is the calculation cycle of DSftR.

  Thereafter, the process proceeds to step 343, where it is determined whether or not the current shift progress rate SftR is equal to or greater than the SftRed. If the shift progress rate SftR has not yet reached the SftRed, this routine is terminated. When the shift progress rate SftR reaches SftRed, the process proceeds to step 344, where the fuel injection return control end flag xEtcFEd is set to ON.

  According to the first embodiment described above, when the ETC cooperative downshift is executed based on the driver's intention to decelerate, the engine output increase control (throttle opening control) increases the engine output regardless of the driver's accelerator operation. In the system that executes the fuel injection return control), the start timing of the engine output increase control is set to the time point when the decrease amount ΔNt of the input shaft rotational speed Nt from the start of the ETC cooperative downshift control becomes the set value K or more. In short, in the first embodiment, focusing on the fact that the input shaft rotational speed Nt decreases as the hydraulic pressure of the disengagement side clutch decreases after the start of the ETC cooperative downshift control, the input shaft rotational speed Nt becomes smaller after the ETC cooperative downshift control starts. When the pressure of the disengagement side clutch is reduced by a predetermined value K or more, it is determined that the oil pressure of the disengagement clutch has dropped below a predetermined transmission torque capacity equivalent oil pressure that does not cause acceleration feeling or shock even when engine output increase control is started. Increase control is started. As a result, the start timing of the engine output increase control can be set with high accuracy, and the driver does not feel the feeling of acceleration or shock due to the engine output increase control. In addition, since the start timing of the engine output increase control can be set without depending on the timer, the engine output increase control can be executed with a simple logic configuration and a small number of parameter settings, and there is an advantage that the practical application is easy.

  By the way, if the fuel cut execution condition such as the accelerator fully closed is satisfied, if the fuel cut is started immediately, a torque shock may occur. As a countermeasure, the engine control ECU 25 prevents a torque shock by executing a fuel cut delay that delays the start of the fuel cut. During fuel cut delay, fuel is injected and engine torque is generated. Therefore, if engine output increase control is started during fuel cut delay, the engine torque becomes too large and the vehicle may be accelerated.

  As a countermeasure, in the first embodiment, as shown in FIG. 22, the elapsed time timer is set at the time t0 when the difference (Ne−Nt) between the engine rotational speed Ne and the input shaft rotational speed Nt becomes equal to or greater than a set value. When a downshift request is generated before the time t2 when the value of the elapsed time timer reaches a set value (predetermined time), the engine output is determined at that time t1 as a downshift request during fuel cut delay. Increase control is prohibited. In short, until the predetermined time has elapsed from the time t0 when the difference (Ne−Nt) between the engine rotational speed Ne and the input shaft rotational speed Nt becomes equal to or greater than the set value, it is determined that the fuel cut delay is in progress and the engine output increase control is performed. Is prohibited. Thereby, it is possible to prevent the engine output increase control from being performed during the period when it is determined that the fuel cut delay is being performed, and it is possible to avoid the adverse effects caused by performing the engine output increase control during the fuel cut delay.

  In the second embodiment of the present invention shown in FIGS. 23 and 24, the gear ratio (= input shaft rotational speed Nt / output shaft rotational speed No) decreases as the input shaft rotational speed Nt decreases after the start of the ETC cooperative downshift control. Paying attention to this point, when the gear ratio drops below the set value after the start of the ETC cooperative downshift control, the disengagement clutch hydraulic pressure does not cause a feeling of acceleration or shock even if the engine output increase control is started. It is determined that the oil pressure has fallen below the torque capacity equivalent hydraulic pressure, and engine output increase control is started.

  This control is executed as follows by the throttle opening control start determination routine of FIG. When this routine is started, it is first determined in step 223 whether or not the gear ratio has fallen below the set value. If the gear ratio has not fallen below the set value, the engine output increase control start timing is determined. This routine is terminated as it is.

Thereafter, when the gear ratio drops below the set value, it is determined that the start timing of the engine output increase control has been reached, the process proceeds from step 223 to step 224, and the throttle opening control start flag xEtcTSt is set to ON. The processing of other routines is the same as that in the first embodiment.
Also in the second embodiment described above, the same effect as in the first embodiment can be obtained.

  Incidentally, as shown in FIG. 25, even after starting the ETC cooperative downshift control, the input shaft rotation speed Nt and the gear ratio may hardly decrease depending on the engine control state. In such a case, in the first and second embodiments, the state where the engine output increase control is not started continues.

  Therefore, in the third embodiment of the present invention shown in FIGS. 25 and 26, an elapsed time timer (timer means) for measuring an elapsed time from the start of the ETC cooperative downshift control is provided, and an elapsed time from the start of the ETC cooperative downshift control. If the engine output increase control is not started even if exceeds the set value, the engine output increase control is started at that time.

  This control is executed as follows by the throttle opening control start determination routine of FIG. When this routine is started, first, at step 223, it is determined whether or not the gear ratio has decreased below the set value. If the gear ratio has not yet decreased below the set value, the routine proceeds to step 225, where ETC coordination is performed. It is determined whether or not the value of the elapsed time timer that measures the elapsed time from the start of downshift control is equal to or greater than the set value.

  Thereafter, if the gear ratio drops below the set value before the elapsed time timer value reaches the set value, the process proceeds from step 223 to step 224, and the throttle opening control start flag xEtcTSt is set to ON.

  On the other hand, if the value of the elapsed time timer reaches the set value without decreasing the gear ratio below the set value, the process proceeds from step 225 to step 224, and the throttle opening control start flag xEtcTSt is set to ON. The processing of other routines is the same as that in the first embodiment.

  In the third embodiment described above, if the engine output increase control is not started even if the elapsed time from the start of the ETC cooperative downshift control exceeds the set value, the engine output increase control is started at that time. Therefore, even when the gear ratio hardly decreases after the start of the ETC cooperative downshift control, the engine output increase control can be started at an appropriate preset timing.

  In step 223, instead of the determination of “gear ratio ≦ setting value?”, The engine output increase control (throttle opening control) is determined by the determination of “ΔNt ≧ setting value?” As in the first embodiment. The start timing may be determined.

  In the fourth embodiment of the present invention shown in FIGS. 27 and 28, the elapsed time timer is activated at the time t0 when the accelerator opening detected by the accelerator sensor 27 becomes less than or equal to the set value, and the value of this elapsed time timer is set. When a downshift request occurs before time t2 when the value (predetermined time) is reached, at time t1, it is determined that the downshift request is during fuel cut delay, and engine output increase control is prohibited.

  This control is executed as follows by the engine output increase control prohibition determination routine of FIG. When this routine is started, it is first determined in step 271 whether or not the accelerator opening detected by the accelerator sensor 27 is within a predetermined time after the accelerator opening becomes equal to or less than a set value. In step 264, the ETC cooperative downshift execution flag xEtc is set to OFF, and engine output increase control (throttle opening control and fuel injection return control) is prohibited.

On the other hand, if the accelerator opening is not less than the set value and is not within the predetermined time, the process proceeds from step 271 to step 272, where it is determined whether the oil temperature is equal to or higher than the set value. If there is, the process proceeds to step 273, the ETC cooperative downshift execution flag xEtc is set to OFF, and engine output increase control (throttle opening control and fuel injection return control) is prohibited.
On the other hand, if the oil temperature is lower than the set value, this routine is terminated without doing anything. In this case, engine output increase control (throttle opening control and fuel injection return control) is permitted.

  In the fourth embodiment described above, it is determined that the fuel cut delay is in progress until the predetermined time has elapsed after the accelerator opening becomes equal to or less than the set value, and the engine output increase control is prohibited. It is possible to prevent the engine output increase control from being performed during the period in which it is determined that the delay is being performed, and it is possible to avoid the adverse effects of performing the engine output increase control during the fuel cut delay.

  In the fifth embodiment of the present invention shown in FIGS. 29 and 30, when the engine ECU 25 is executing the fuel cut delay, information on the fuel cut delay (fuel cut delay flag) is sent from the engine ECU 25 to the AT-ECU 70. The engine output increase control is prohibited when a downshift request occurs during fuel cut delay.

  This control is executed as follows by the engine output increase control prohibition determination routine of FIG. When this routine is started, first, at step 281, it is determined whether or not the fuel cut delay is being performed based on the fuel cut delay information transmitted from the engine ECU 25 to the AT-ECU 70. If there is, the process proceeds to step 283, the ETC cooperative downshift execution flag xEtc is set to OFF, and engine output increase control (throttle opening control and fuel injection return control) is prohibited.

On the other hand, if it is determined in step 281 that the fuel cut delay is not in progress, the process proceeds to step 282, where it is determined whether the oil temperature is equal to or higher than a set value. Then, the ETC cooperative downshift execution flag xEtc is set to OFF, and engine output increase control (throttle opening control and fuel injection return control) is prohibited.
On the other hand, if the oil temperature is lower than the set value, this routine is terminated without doing anything. In this case, engine output increase control (throttle opening control and fuel injection return control) is permitted.

  In the fifth embodiment described above, fuel cut delay information is directly acquired from the engine ECU 25, and engine output increase control (throttle opening control and fuel injection return control) during fuel cut delay can be reliably prohibited.

  In Embodiment 6 of the present invention shown in FIG. 31, the fuel cut is executed between the start timing t1 of the ETC cooperative downshift control and the start timing t2 of the engine output increase control. When the ETC cooperative downshift control is started, the release side clutch hydraulic pressure command value is immediately lowered to or near the minimum hydraulic pressure (0 kPa) to immediately eliminate the release side clutch transmission torque capacity. Even if the fuel cut is started, torque shock does not occur, the input shaft rotation speed Nt and gear ratio can be reduced, and the start timing of the engine output increase control is advanced to advance the downshift speed quickly. Can be made.

  In the seventh embodiment of the present invention shown in FIGS. 32 and 33, the fuel cut is performed only when the fuel cut delay is in progress between the start timing t1 of the ETC cooperative downshift control and the start timing t2 of the engine output increase control. To do. That is, even during the period from the start timing t1 of the ETC cooperative downshift control to the start timing t2 of the engine output increase control, the fuel cut is not executed unless the fuel cut delay is in progress. In this way, the fuel cut is executed when the fuel is injected with a request other than the fuel cut delay, such as when a small amount of fuel is injected to maintain the engine rotation in the low rotation region. It is possible to prevent the occurrence of problems such as engine stalls.

  This control is executed as follows by the fuel injection return control routine of FIG. When this routine is started, first, in step 300, it is determined whether or not a fuel cut request is generated on the engine control side based on the fuel cut information transmitted from the engine ECU 25 to the AT-ECU 70, and the fuel cut is performed. If the request has not occurred, the process proceeds to step 310 to determine whether or not the fuel cut delay is being performed. As a result, if it is determined that the fuel cut delay is not in progress, this routine is terminated as it is, but if it is determined that the fuel cut delay is in progress, the routine proceeds to step 311 to execute the fuel cut.

  If it is determined in step 300 that a fuel cut request is generated on the engine control side, the fuel injection or fuel cut is performed in the same manner as the fuel injection return control routine of FIG. 19 of the first embodiment. To implement.

  In the seventh embodiment described above, the fuel cut is not executed unless the fuel cut delay is in progress even during the period from the start timing t1 of the ETC cooperative downshift control to the start timing t2 of the engine output increase control. Therefore, when a small amount of fuel is being injected to maintain engine rotation in the low speed range, such as when fuel is being injected with a request other than the fuel cut delay, the fuel cut is executed and the engine stalled. Can be prevented from occurring.

  By the way, if the accelerator pedal is depressed even a little after the start of the ETC cooperative downshift control, the input shaft rotation speed is unlikely to decrease, and there is a possibility that the engine output increase control will not start.

  Therefore, in the eighth embodiment of the present invention shown in FIG. 34, in addition to the case where the fuel cut delay is being performed between the start timing t1 of the ETC cooperative downshift control and the start timing t2 of the engine output increase control, The fuel cut is also executed when the opening is equal to or less than the predetermined value (step 312). In this way, even when the accelerator pedal is depressed a little after the start of the ETC cooperative downshift control, the engine output increase control can be started by reducing the input shaft rotational speed Nt by the fuel cut.

  In each of the above embodiments, the engine output increase control is realized by throttle opening control + fuel injection return control. However, fuel increase control or ignition delay control is added to one of the engine output increase controls. Alternatively, even if the throttle opening control + fuel injection return control is replaced with the fuel increase control or the ignition retard control, the engine output increase control can be realized based on the same concept. Further, each of the above embodiments is an embodiment of a gasoline engine. However, even in a diesel engine, the present invention can be realized by executing control for increasing the fuel injection amount as engine output increase control.

It is a schematic block diagram of the whole engine control system of each Example of this invention. It is a figure which shows schematic structure of the whole automatic transmission. It is a figure which shows typically the mechanical structure of an automatic transmission. It is a figure which shows the combination of engagement / release of clutch C0-C2 and brake B0, B1 for every gear stage. It is a figure which shows an example of a transmission pattern. It is a time chart which shows an example of power-on downshift control. 3 is a time chart illustrating an example of ETC cooperative downshift control according to the first embodiment. 6 is a flowchart illustrating a flow of processing of a shift control routine according to the first embodiment. 6 is a flowchart illustrating a process flow of a shift type determination routine according to the first embodiment. 3 is a flowchart showing a flow of processing of a transmission hydraulic pressure control routine according to the first embodiment. 6 is a flowchart illustrating a processing flow of a release side clutch hydraulic pressure control routine according to the first embodiment. 3 is a flowchart illustrating a process flow of an engagement side clutch hydraulic pressure control routine according to the first embodiment. 4 is a flowchart illustrating a flow of processing of a throttle opening control routine according to the first embodiment. 6 is a flowchart showing a flow of processing of a throttle opening control start determination routine according to the first embodiment. 6 is a flowchart illustrating a flow of processing of a throttle opening control end determination routine according to the first embodiment. 7 is a flowchart illustrating a flow of processing of a throttle opening amount correction routine according to the first embodiment. It is a figure which shows an example of the throttle opening amount setting map of Example 1. FIG. 6 is a flowchart showing a flow of processing of an engine output increase control prohibition determination routine of Embodiment 1. 3 is a flowchart showing a flow of processing of a fuel injection return control routine of Embodiment 1. 3 is a flowchart illustrating a flow of processing of a fuel injection start determination routine according to the first embodiment. 6 is a flowchart illustrating a flow of processing of a fuel injection end determination routine according to the first embodiment. 6 is a time chart illustrating a second example of ETC cooperative downshift control according to the first embodiment. 6 is a time chart illustrating an example of ETC cooperative downshift control according to the second embodiment. 7 is a flowchart illustrating a flow of processing of a throttle opening control start determination routine according to a second embodiment. 10 is a time chart illustrating an example of ETC cooperative downshift control according to a third embodiment. 10 is a flowchart illustrating a flow of processing of a throttle opening control start determination routine according to a third embodiment. 10 is a time chart illustrating an example of ETC cooperative downshift control according to a fourth embodiment. 12 is a flowchart showing a flow of processing of an engine output increase control prohibition determination routine according to a fourth embodiment. 10 is a time chart illustrating an example of ETC cooperative downshift control according to a fifth embodiment. FIG. 10 is a flowchart illustrating a process flow of an engine output increase control prohibition determination routine according to a fifth embodiment. 10 is a time chart illustrating an example of ETC cooperative downshift control according to a sixth embodiment. FIG. 18 is a flowchart illustrating a process flow of a fuel injection return control routine according to a seventh embodiment. 18 is a time chart illustrating an example of ETC cooperative downshift control according to a seventh embodiment. FIG. 18 is a flowchart illustrating a process flow of a fuel injection return control routine according to an eighth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake pipe, 14 ... Air flow meter, 15 ... Throttle valve, 17 ... Motor, 18 ... Throttle opening sensor, 24 ... Crank angle sensor (engine speed detection means), 25 ... Engine ECU (engine control computer, engine output increase control means), 26 ... accelerator pedal, 27 ... accelerator sensor (accelerator opening detection means), 51 ... automatic transmission, 52 ... torque converter, 53 ... transmission gear mechanism (transmission mechanism) 56 ... Lock-up clutch, 57 ... Hydraulic control circuit, 58 ... Hydraulic pump, 59 ... Line pressure control circuit, 60 ... Automatic shift control circuit, 61 ... Lock-up control circuit, 66 ... Manual switching valve, 68 ... Rotating input shaft Speed sensor (input shaft rotational speed detecting means), 69... Output shaft rotational speed sensor (output shaft rotational speed detecting means) , 70 ... AT-ECU (downshift control means, engine output increase control means, the timer means), C0 to C2 ... clutch (frictional engagement element), B0, B1 ... brake (friction engagement element)

Claims (7)

By controlling the hydraulic pressure applied to the plurality of friction engagement elements individually by the hydraulic pressure control means, the automatic transmission of the automatic transmission that selectively switches the engagement and release of each friction engagement element and switches the shift stage of the transmission mechanism. In the control device,
Downshift control means for controlling the hydraulic pressure so as to downshift the speed change mechanism to the gear position where the engine brake works based on the driver's intention to decelerate;
Engine output increase control means for executing engine output increase control for increasing the engine output regardless of the driver's accelerator operation during the downshift control;
Input shaft rotation speed detection means for detecting the input shaft rotation speed of the speed change mechanism;
Output shaft rotational speed detection means for detecting the output shaft rotational speed of the speed change mechanism;
Fuel cut execution means for executing fuel cut,
The engine output increase control means sets the start timing of the engine output increase control as a time point when the ratio of the input shaft rotation speed and the output shaft rotation speed of the transmission mechanism decreases to a predetermined value or less.
The fuel cut means, only when the engine control computer is running fuel cut delay for delaying the start of the fuel cut, the fuel cut started from a state that injecting the downshift control start or al fuel Then, the fuel transmission is executed until the start timing of the engine output increase control . The control apparatus for an automatic transmission according to claim 1, wherein the fuel cut execution means executes fuel cut even when the accelerator opening is equal to or less than a predetermined value. By controlling the hydraulic pressure applied to the plurality of friction engagement elements individually by the hydraulic pressure control means, the automatic transmission of the automatic transmission that selectively switches the engagement and release of each friction engagement element and switches the shift stage of the transmission mechanism. In the control device,
Downshift control means for controlling the hydraulic pressure so as to downshift the speed change mechanism to the gear position where the engine brake works based on the driver's intention to decelerate;
Engine output increase control means for executing engine output increase control for increasing the engine output regardless of the driver's accelerator operation during the downshift control;
Input shaft rotation speed detection means for detecting the input shaft rotation speed of the speed change mechanism;
Output shaft rotation speed detection means for detecting the output shaft rotation speed of the transmission mechanism;
The engine output increase control means includes means for setting the start timing of the engine output increase control when the ratio between the input shaft rotational speed and the output shaft rotational speed of the transmission mechanism falls below a predetermined value; A control device for an automatic transmission, comprising: means for prohibiting the engine output increase control during a period in which it is determined that a fuel cut delay that delays the start of fuel cut is being executed. Means for calculating the difference between the engine speed and the input shaft speed;
The engine output increase control means includes means for prohibiting the engine output increase control when a downshift request is generated within a predetermined time after the difference between the engine rotation speed and the input shaft rotation speed exceeds a predetermined value. The control device for an automatic transmission according to claim 3 , wherein Accelerator opening detection means for detecting the accelerator opening,
The engine output increase control means includes means for prohibiting the engine output increase control when a downshift request is generated within a predetermined time after the accelerator opening becomes equal to or less than a predetermined value. Item 5. The automatic transmission control device according to Item 3 or 4 . The engine output increase control means includes means for receiving information on the fuel cut delay from the engine control computer when the engine control computer is executing a fuel cut delay that delays the start of fuel cut, and during the fuel cut delay. control system for an automatic transmission according to any one of claims 3 to 5, characterized in that the downshift request is a means for inhibiting said engine output increasing control when that occurred. 7. The downshift control unit according to any one of claims 3 to 6 , wherein when the downshift control is started, the hydraulic pressure command value of the disengagement side frictional engagement element is immediately lowered to or near the minimum hydraulic pressure. A control device for an automatic transmission according to claim 1.

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